[TRTLLM-15344][feat] nixl bounce v2 (6/6): NixlTransferAgent integration - #17608
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[TRTLLM-15344][feat] nixl bounce v2 (6/6): NixlTransferAgent integration#17608chuangz0 wants to merge 6 commits into
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Buddy allocator, shared data arena, execution-context pool, and the gather/scatter CUDA kernel, plus their unit tests. These are the dependency-free building blocks of the NIXL bounce-buffer v2 transport; nothing is wired into production paths yet. Signed-off-by: Chuang Zhu <111838961+chuangz0@users.noreply.github.com>
Bounce config (env-var parsing), wire message codec (control-plane messages + capability handshake encode/decode), and the transfer-plan builder that maps a TransferRequest onto bounce chunks. Unit-tested; still not reachable from production paths. Signed-off-by: Chuang Zhu <111838961+chuangz0@users.noreply.github.com>
ControlChannel interface with ZMQ and NIXL-notification implementations, plus the TransferEngine abstraction and its NIXL implementation. The top-level cppzmq fetch is decoupled from ENABLE_UCX so bounce only needs NIXL + zmq. The NIXL-backed sources gain their first consumers in the transport PR (5/6); the zmq channel is unit-tested here. Signed-off-by: Chuang Zhu <111838961+chuangz0@users.noreply.github.com>
Credit-based scheduler that hands out bounce-buffer credits over the buddy allocator, with anti-starvation handling for large chunks. Heavily unit-tested (fairness, starvation, recycling, concurrency). Signed-off-by: Chuang Zhu <111838961+chuangz0@users.noreply.github.com>
The BounceTransport reactor: gather -> RDMA write into the remote bounce arena -> scatter, driven by credits from the scheduler and the control channel from PR 3/6. Compiled into the NIXL wrapper behind TLLM_BOUNCE_V2 (zmq-gated) but not yet reachable: the NixlTransferAgent integration and the runtime opt-in land in PR 6/6. Covered by real-NIXL reactor tests (byte-exact round-trip, failure paths, optional TSan variant). Signed-off-by: Chuang Zhu <111838961+chuangz0@users.noreply.github.com>
Wires the bounce transport into production: AgentDesc gains an optional bounce capability handshake, NixlTransferAgent owns the transport behind a pimpl and routes eligible requests via shouldUseBounce (opt-in with TRTLLM_NIXL_BOUNCE_ENABLE, off by default), plus python bindings for programmatic engagement checks. Adds the two end-to-end tests (real-NIXL loopback and public-agent-API path), CI wiring (l0_h100), and a python single-process transceiver test. Signed-off-by: Chuang Zhu <111838961+chuangz0@users.noreply.github.com>
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@coderabbitai summary
Description
Part 6/6 (final) of splitting the NIXL bounce-buffer v2 transport (#15780) into reviewable pieces. This PR wires the transport into production:
AgentDescgains an optional bounce capability handshake blob (backward-compatible: empty when bounce is disabled; serialized alongside the existing backend blob + VMM regions)NixlTransferAgentowns the transport behind a pimpl (bounce::NixlBounceState) and routes eligible requests viashouldUseBounce; runtime opt-in withTRTLLM_NIXL_BOUNCE_ENABLE(off by default — when unset the agent behaves exactly as before)isBounceEnabled()/getBounceSubmitCount()+ nanobind bindings, so tests and deployments can verify engagement programmatically instead of grepping logsexecutor_bouncepre-merge group (added in part 1) now fails ifbounceAgentE2ETestwas not built, so pre-merge cannot silently lose the NIXL E2E coverage; adds the python single-process cache-transceiver test tol0_h100.ymlStack: part 6/6, stacked on #17607 — review only the last commit (
nixl bounce v2 (6/6)). Umbrella: #15780.Test Coverage
cpp/tests/unit_tests/executor/bounce/bounceNixlE2ETest.cpp— real-NIXL loopback: two real agents, real RDMAcpp/tests/unit_tests/executor/bounce/bounceAgentE2ETest.cpp— production path: bounce engaged viaNixlTransferAgent::submitTransferRequests, public agent API onlytests/unittest/disaggregated/test_cache_transceiver_single_process.py— python-level transceiver test with bounce enabledtest_unit_tests[executor_bounce-90](pre-merge since part 1) picks up the two new E2E gtests automatically and now enforces that they were builtPR Checklist
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